1. Field of the Invention
The present invention relates to a fuel cell system, and in particular, to a carbon monoxide remover which reduces the concentration of carbon monoxide in the reforming gas generated from a reformer.
2. Description of Related Art
Generally, a fuel cell is an electric power system which directly converts the energy of the chemical reaction of hydrogen in a hydrocarbon-based material such as methanol with oxygen or an oxygen-containing gas such as air, into electrical energy.
The fuel cell uses hydrogen made through reforming methanol or ethanol as a fuel, and has advantages in a wide range of uses such as mobile power for cars, distributed power for households and public buildings, and power for electronic appliances.
A fuel cell system is basically a stack, a fuel processor, a fuel tank and a fuel pump. The fuel processor includes a reformer for reforming a fuel to generate hydrogen, and a carbon monoxide (CO) remover for reducing the concentration of carbon monoxide in the hydrogen gas through a oxidation reaction of the hydrogen with oxygen (or air, referred to hereinafter as air). The CO remover, commonly known as a preferential CO oxidation (PROX) reactor, includes a reactor body with an inner space, and an oxidation catalyst provided therein.
However, with the CO remover, as pressured hydrogen and pressurized air are supplied to the reactor body, a channeling phenomenon is generated, in which hydrogen and air are concentrated in the center of the reactor body.
With the channeling phenomenon, the oxidation reaction of hydrogen and air by the oxidation catalyst occurs more intensely at the center of the reactor body, and the activity of the oxidation catalyst is diminished. For this reason, a conventional CO remover has lower efficiency, and cannot be effectively used for a fuel cell system.